FDC37C672QFP SMSC Corporation, FDC37C672QFP Datasheet - Page 24

• Manufacturer Part Number: FDC37C672QFP
• Description: ENHANCED SUPER I/O CONTROLLER WITH FAST IR
• Manufacturer: SMSC Corporation

6.1.4
SMSC FDC37C672
Bit 7
X
X
X
1
0
DIGITAL OUTPUT REGISTER
Bit 6
BIT 7 MOTOR ENABLE 3
This bit controls the MTR3 disk interface output. A logic "1" in this bit causes the output to go active.
Tape Drive Register (TDR)
Address 3F3 READ/WRITE
The Tape Drive Register (TDR) is included for 82077 software compatibility and allows the user to assign
tape support to a particular drive during initialization. Any future references to that drive automatically
invokes tape support. The TDR Tape Select bits TDR.[1:0] determine the tape drive number. Table 6.3
illustrates the Tape Select Bit encoding. Note that drive 0 is the boot device and cannot be assigned tape
support.
unaffected by a software reset.
X
X
X
1
0
Bit 5
X
X
X
1
0
The remaining Tape Drive Register bits TDR.[7:2] are tristated when read.
Bit 4
X
X
X
1
0
TAPE SEL1
Bit1
Table 6.4 - Internal 2 Drive Decode - Normal
X
0
0
1
1
(TDR.1)
Table 6.2 - Drive Activation Values
0
0
1
1
DRIVE
Bit 0
Table 6.3 - Tape Select Bits
DATASHEET
0
1
2
3
X
0
1
0
1
TAPE SEL0
DRIVE SELECT OUTPUTS
(TDR.0)
Page 24
nDS1
0
1
0
1
1
0
1
1
1
(ACTIVE LOW)
DOR VALUE
1CH
2DH
4EH
8FH
SELECTED
nDS0
DRIVE
None
0
1
1
1
1
1
2
3
Enhanced Super I/O Controller with Fast IR
nMTR1
MOTOR ON OUTPUTS
nBIT 5
nBIT 5
nBIT 5
nBIT 5
nBIT 5
(ACTIVE LOW)
The TDR is
Rev. 10-29-03
nMTR0
nBIT 4
nBIT 4
nBIT 4
nBIT 4
nBIT 4
Datasheet